Incremental peritoneal dialysis and survival outcomes: a propensity-matched cohort study

Background The advantages of an incremental dialysis start are not fully clear. We aimed to evaluate the association of incremental initiation of peritoneal dialysis with mortality. Methods Incident peritoneal dialysis patients with a catheter placed at our hospital between 2008 and 2017 were included. All patients were followed up until December 31, 2019. Patients were categorized into different groups according to the initial daily dialysis exchanges, and were matched at a ratio of 1:2 with propensity score matching. Multiple variables including age, sex, residual kidney function, urine volume, hemoglobin, serum albumin and other important variables were included for the matching. Primary outcomes were all-cause and cardiovascular mortality. Results A total of 1315 patients with a mean age of 45.9 years were enrolled. The mean glomerular filtration rate was 4.32 ml/min/1.73 m 2 at start of dialysis. Two hundred eighty-five patients in the incremental group and 502 in the full dose group were matched for age, sex, residual kidney function, urine volume, hemoglobin, serum albumin and other important variables. Patient survival and cardiovascular event-free survival were similar between the two groups. However, during the first 6 years of peritoneal dialysis, patients in the incremental group had better survival ( P = 0.011) and cardiovascular event-free survival ( P = 0.044) than the full dose group, while such advantages disappeared when dialysis vintage became longer. Further analysis showed that the incremental group ( vs full dose dialysis) had a 39% lower risk (95% CI 0.42–0.90, P = 0.012) of all-cause mortality and a 41% decreased risk (95% CI 0.35–0.99, P = 0.047) of cardiovascular mortality during the first 6 years of dialysis. Additionally, the cumulative hazard for anuria was significantly lower in the incremental group versus the full dose group ( P = 0.006). Conclusions Our study shows a time-related survival advantage for incremental peritoneal dialysis patients, suggesting that an incremental regimen for starting peritoneal dialysis is feasible and is not associated with worse outcomes. Graphical abstract Graphical Abstract presenting schematically the measurements of the solvation response function by processing the relevant streak camera images and the time-correlated photon counting (TCSPC) data and appropriately combining them together.